Fingerprint unlocking method and terminal

ABSTRACT

A fingerprint unlocking method and a terminal are provided. The method may be applied to a terminal having an in-screen fingerprint detection function. When the terminal is in a screen-locked state, the terminal determines whether an operation of a user meets a preset condition. If the operation of the user meets the preset condition, a fingerprint recognition identifier is displayed on a touch display screen of the terminal. A display area of the fingerprint recognition identifier is an area in which fingerprint recognition can be performed. The method resolves a problem that the user cannot perform fingerprint unlocking because the user cannot see a position of a fingerprint detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of International Application No.PCT/CN2018/080552, filed on Mar. 26, 2018, which is hereby incorporatedby reference in its entirety.

TECHNICAL FIELD

This application relates to the field of terminal technologies, and inparticular, to a fingerprint unlocking method and a terminal.

BACKGROUND

With rapid development of a touch display screen, an intelligentterminal having a relatively high screen-to-body ratio (a ratio of anarea of a screen to an area of a front panel of a terminal) graduallybecomes a mainstream product in the market.

For a terminal using front-facing fingerprint detection, if afingerprint key is still used, an increase of the screen-to-body ratiois greatly limited. To meet a use habit of a user accustomed to usingfront-facing fingerprint recognition and ensure that the terminal has arelatively high screen-to-body ratio, a solution is provided accordingto an in-screen fingerprint detection technology. In-screen fingerprintdetection is that a fingerprint detector is placed below the touchdisplay screen, and the user places a finger on the touch display screenabove the fingerprint detector to implement fingerprint detection.

In a fingerprint key detection solution, the user may see a position ofthe fingerprint key and perform detection. However, in an in-screenfingerprint detection solution, the user cannot intuitively determine aposition of the fingerprint detector. In a scenario in which the userneeds to perform fingerprint recognition, especially when a screen needsto be unlocked with a fingerprint, how to notify the user of theposition of the fingerprint detector becomes an urgent problem to beresolved currently.

SUMMARY

Embodiments of this application provide a fingerprint unlocking methodand a terminal. The method may be applied to a terminal that uses anin-screen fingerprint detection solution, to display a fingerprintrecognition area for a user, so that the user can perform fingerprintrecognition.

According to a first aspect, an embodiment of this application providesa fingerprint unlocking method. The method includes:

when a terminal is in a screen-locked state, determining, by theterminal whether an operation of a user meets a preset condition; and ifthe operation of the user meets the preset condition, displaying afingerprint recognition identifier on a touch display screen of theterminal, where a display area of the fingerprint recognition identifieris an area in which fingerprint recognition can be performed.

In the foregoing manner, when detecting that the operation of the usermay be an operation intended for fingerprint unlocking, the terminaldisplays the fingerprint recognition identifier in the area in whichfingerprint recognition can be performed, so that the user performsfingerprint recognition in the display area. This resolves a problemthat the user cannot perform fingerprint recognition because the usercannot see a position of a fingerprint detector.

With reference to the first aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screenor performs a floating operation on the touch display screen, and thedetermining, by the terminal, whether an operation of a user meets apreset condition is:

determining, by the terminal based on a capacitance signal generated bythe operation of the user on the touch display screen, whether thecapacitance signal is greater than or equal to a capacitance value of apreset threshold, or is less than or equal to the capacitance value ofthe preset threshold.

With reference to the first aspect, in a possible implementation, theoperation of the user is that the user performs a floating operation onthe touch display screen, and the determining, by the terminal, whetheran operation of a user meets a preset condition is:

determining, by the terminal based on a capacitance signal generated bythe operation of the user on the touch display screen, whether adistance between a finger of the user and the touch display screen isless than or equal to a preset threshold.

With reference to the first aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screen,and the determining, by the terminal, whether an operation of a usermeets a preset condition is:

determining, by the terminal based on a capacitance signal generated bythe operation of the user on the touch display screen, whether an areain which a finger of the user touches the touch display screen is in apreset area, where the preset area is the area in which fingerprintrecognition can be performed.

With reference to the first aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screenor performs a floating operation on the touch display screen, and thedetermining, by the terminal, whether an operation of a user meets apreset condition is:

determining, by the terminal based on a capacitance signal generated bythe operation of the user on the touch display screen, whether a fingerof the user slides from an area far away from the area in whichfingerprint recognition can be performed toward the area in whichfingerprint recognition can be performed.

With reference to the first aspect, in a possible implementation, theoperation of the user is an operation of the user on a phone key, andthe determining, by the terminal, whether an operation of a user meets apreset condition is:

determining, by the terminal based on a signal generated by theoperation of the user on the phone key, whether the user presses anon/off key or a volume key, or whether the user simultaneously presses avolume-up key and a volume-down key.

With reference to the first aspect, in a possible implementation, afterthe terminal determines that the operation of the user meets the presetcondition, the method further includes:

starting, by the terminal, a fingerprint detector.

According to a second aspect, an embodiment of this application furtherprovides a terminal. The terminal includes a processor, a touch displayscreen, and a fingerprint detector. The fingerprint detector is built inthe terminal. The processor is configured to:

when the terminal is in a screen-locked state, determine whether anoperation of a user meets a preset condition; and

if the operation of the user meets the preset condition, control thetouch display screen to display a fingerprint recognition identifier,where a display area of the fingerprint recognition identifier is anarea in which fingerprint recognition can be performed.

With reference to the second aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screenor performs a floating operation on the touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether the capacitance signal isgreater than or equal to a capacitance value of a preset threshold.

With reference to the second aspect, in a possible implementation, theoperation of the user is that the user performs a floating operation onthe touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether a distance between afinger of the user and the touch display screen is less than or equal toa preset threshold, or is less than or equal to a capacitance value ofthe preset threshold.

With reference to the second aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether an area in which a fingerof the user touches the touch display screen is in a preset area, wherethe preset area is the area in which fingerprint recognition can beperformed.

With reference to the second aspect, in a possible implementation, theoperation of the user is that the user touches the touch display screenor performs a floating operation on the touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether a finger of the userslides from an area far away from the area in which fingerprintrecognition can be performed toward the area in which fingerprintrecognition can be performed.

With reference to the second aspect, in a possible implementation, theoperation of the user is that an operation of the user on a phone key.

The processor is specifically configured to:

determine, by the terminal based on a signal generated by the operationof the user on the phone key, whether the user presses an on/off key ora volume key, or whether the user simultaneously presses a volume-up keyand a volume-down key.

With reference to the second aspect, in a possible implementation, afterdetermining that the operation of the user meets the preset condition,the processor is further configured to:

enable or disable a fingerprint detector.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of an appearance of a conventionalterminal according to an embodiment of this application;

FIG. 2 is a schematic diagram of an appearance of a terminal accordingto an embodiment of this application;

FIG. 3 is a schematic diagram of a structure of a terminal according toan embodiment of this application;

FIG. 4 is a first schematic flowchart of a fingerprint unlocking methodaccording to an embodiment of this application;

FIG. 5 is a schematic diagram of an effect of a fingerprint unlockingmethod according to an embodiment of this application;

FIG. 6(a) and FIG. 6(b) are a first schematic diagram of a capacitancesignal of a touch display screen according to an embodiment of thisapplication;

FIG. 7 is a second schematic diagram of a capacitance signal of a touchdisplay screen according to an embodiment of this application;

FIG. 8 is a schematic diagram of a movement direction of a finger of auser according to an embodiment of this application;

FIG. 9 is a second schematic flowchart of a fingerprint unlocking methodaccording to an embodiment of this application; and

FIG. 10 is a third schematic flowchart of a fingerprint unlocking methodaccording to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

The following further describes in detail the embodiments of thisapplication with reference to accompanying drawings.

Because a fingerprint recognition technology is relatively mature andhas advantages of high security, a fast recognition speed, a highrecognition success rate and the like, the fingerprint recognitiontechnology has been widely applied to intelligent terminals. A user mayperform operations such as screen-unlocking and payment throughfingerprint recognition instead of password input.

As shown in FIG. 1 , on a conventional terminal, a fingerprint detectormay be disposed on a front panel of the terminal, or may be disposed ona rear panel of the terminal. The user may select, based on an operationhabit of the user, a terminal with front-facing fingerprint recognitionor a terminal with rear-facing fingerprint recognition. When theterminal is in a screen-locked state, an integrated circuit of a touchdisplay screen is usually in a power-off state, namely, a non-workingstate, but an integrated circuit of the fingerprint detector is in aworking state. When the terminal is in the screen-locked state, the usermay place a finger on the fingerprint detector, to complete fingerprintrecognition and unlock a screen.

With development of terminal technologies, for better visual experience,a screen-to-body ratio gradually becomes a concern of consumers andterminal manufacturers. The screen-to-body ratio is a ratio of an areaof the screen to an area of the front panel of the terminal. A higherscreen-to-body ratio can provide better visual experience for the user.Therefore, the consumers favor a terminal with a higher screen-to-bodyratio.

In a design for increasing the screen-to-body ratio of the terminal, tomeet a requirement of a user who prefers to use the front-facingfingerprint recognition, a designer proposes that the fingerprintdetector is disposed below a touch display screen panel, that is,in-screen fingerprint detection, as shown in FIG. 2 . The user mayimplement fingerprint recognition by placing the finger on the touchdisplay screen.

However, because the fingerprint detector is disposed below the touchdisplay screen, the user cannot see a position of the fingerprintdetector. This is difficult for the user to unlock or perform anotheroperation with a fingerprint.

To resolve the foregoing technical problem, the embodiments of thisapplication provides a fingerprint unlocking method. The method isapplied to a terminal that uses an in-screen fingerprint detectionsolution, to display a fingerprint recognition area for the user, sothat the user can perform fingerprint recognition.

The terminal in the embodiments of the present invention may include amobile phone, a tablet computer, a personal digital assistant (personaldigital assistant, PDA), and the like.

An example in which the terminal is a mobile phone is used. FIG. 3 showsa block diagram of a partial structure of a mobile phone 300 related toan embodiment of the present invention. Refer to FIG. 3 . The mobilephone 300 may include components such as a radio frequency (radiofrequency, RF) circuit 310, a memory 320, another input device 330, atouch display screen 340, a fingerprint detector 350, a sensor 360, anaudio circuit 370, an I/O subsystem 380, a processor 390, and a powersupply 3100. A person skilled in the art may understand that thestructure of the mobile phone shown in FIG. 3 does not constitute alimitation on the terminal to which the embodiments of this applicationare applicable. The terminal to which the embodiments of thisapplication are applicable may include more or fewer components thanthose shown in the figure, or some components may be combined, or somecomponents may be separated, or the components may be disposed indifferent manners.

The following describes each component of the mobile phone 300 in detailwith reference to FIG. 3 .

The RF circuit 310 may be configured to send and receive a signal in aninformation receiving and sending process or a call process. Inparticular, after receiving downlink information from a base station,the RF circuit 310 sends the downlink information to the processor 390for processing, and sends related uplink data to the base station.Generally, an RF circuit includes but is not limited to an antenna, atleast one amplifier, a transceiver, a coupler, a low noise amplifier(low noise amplifier, LNA), a duplexer, and the like. In addition, theRF circuit 310 may further communicate with a network and another devicethrough wireless communication. The wireless communication may use anycommunications standard or protocol, including but not limited to aglobal system for mobile communications (global system of mobilecommunication, GSM), a general packet radio service (general packetradio service, GPRS), code division multiple access (code divisionmultiple access, CDMA), wideband code division multiple access (widebandcode division multiple access, WCDMA), long term evolution (long termevolution, LTE), a fifth generation (the fifth generation, 5G) mobilecommunications system, an email, a short messaging service (shortmessaging service, SMS), and the like.

The memory 320 may be configured to store a software program and amodule. The processor 390 runs the software program and the module thatare stored in the memory 320, to perform various function applicationsof the mobile phone 300 and data processing. The memory 320 may includea program storage area and a data storage area. The program storage areamay store an operating system, an application program required by atleast one function (such as a sound playing function or an image playingfunction), and the like. The data storage area may store data (such asaudio data or video data) created based on use of the mobile phone 300,and the like. In addition, the memory 320 may include a high-speedrandom access memory, and may further include a non-volatile memory,such as at least one magnetic disk storage device, a flash memorydevice, or another volatile solid-state storage device.

The another input device 330 may be configured to receive input digit orcharacter information, and generate a key signal input related to usersetting and function control of the mobile phone 300. Specifically, theanother input device 330 may include but is not limited to a functionkey (such as a volume control key or an on/off key), a camera, and thelike. The another input device 330 is connected to another input devicecontroller 381 in the I/O subsystem 380, and exchanges a signal with theprocessor 390 under control of the another input device controller 381.

The touch display screen 340 may be configured to display informationprovided for a user or information input by the user and various menusof the mobile phone 300, and may further receive a user input.Specifically, the touch display screen 340 may include a display panel341 and a touch panel 342. The display panel 341 may be configured in aform of a liquid crystal display (liquid crystal display, LCD), anorganic light-emitting diode (organic light-emitting diode, OLED), orthe like. The touch panel 342, also referred to as a touchscreen, atouch-sensitive screen, or the like, may collect a touch or non-touchoperation (for example, an operation performed by the user on the touchpanel 342 or near the touch panel 342 by using any proper object oraccessory, such as a finger or a stylus, or may include a motion sensingoperation, where the operation includes operation types such as asingle-point control operation and a multipoint control operation) ofthe user on or near the touch panel 342, and drive a correspondingconnection apparatus according to a preset program. Optionally, thetouch panel 342 may include two parts: a touch detection apparatus and atouch controller. The touch detection apparatus detects a touchorientation and gesture of the user, detects a signal brought by thetouch operation, and sends the signal to the touch controller. The touchcontroller receives touch information from the touch detectionapparatus, converts the touch information into information that can beprocessed by the processor, and then sends the information to theprocessor 390. In addition, the touch controller may further receive andexecute a command sent by the processor 390. Further, the touch panel342 may cover the display panel 341. The user may perform, based oncontent displayed on the display panel 341 (the displayed contentincludes but is not limited to a soft keyboard, a virtual mouse, avirtual key, an icon, and the like), an operation on or near the touchpanel 342 that covers the display panel 341. After detecting theoperation on or near the touch panel 342, the touch panel 341 sends theoperation to the processor 390 by using the I/O subsystem 380 todetermine the user input. Then, the processor 390 provides, based on theuser input, corresponding visual output on the display panel 341 byusing the I/O subsystem 380. In FIG. 3 , the touch panel 342 and thedisplay panel 341 serve as two independent components to implement inputand input functions of the mobile phone 300. However, in someembodiments, the touch panel 342 and the display panel 341 may beintegrated to implement the input and output functions of the mobilephone 300.

The fingerprint detector 350 is configured to recognize a fingerprint ofthe user, for example, when fingerprint unlocking or fingerprint paymentis performed, detect whether the fingerprint input by the user is avalid fingerprint.

The mobile phone 300 may further include at least one sensor 360, forexample, an acceleration sensor 361, an optical sensor, and anothersensor. Specifically, the acceleration sensor 361 may detect magnitudeof accelerations in various directions (usually on three axes), anddetect magnitude and a direction of gravity when the acceleration sensoris still, and may be applied to an application for identifying a mobilephone posture (such as screen switching between a landscape mode and aportrait mode, a related game, and magnetometer posture calibration), afunction related to vibration recognition (for example, a pedometer, ora knock), and the like. The optical sensor may include an ambient lightsensor and a proximity sensor. The ambient light sensor may adjustbrightness of the touch display screen 340 based on light and shade ofambient light. The proximity sensor may turn off the screen and/orbacklight when the mobile phone 300 moves to an ear. Other sensors suchas a gyroscope, a barometer, a hygrometer, a thermometer, and aninfrared sensor may be further disposed on the mobile phone 300. Detailsare not described herein.

The audio circuit 370, a loudspeaker 371, and a microphone 372 mayprovide an audio interface between the user and the mobile phone 300.The audio circuit 370 may transmit a signal converted from receivedaudio data to the loudspeaker 371, and the loudspeaker 371 converts thesignal into a sound signal for outputting. In addition, the microphone372 converts a collected sound signal into a signal, and the audiocircuit 370 converts the signal into audio data after receiving thesignal, and then outputs the audio data to the RF circuit 310 to sendthe audio data to, for example, another mobile phone, or outputs theaudio data to the memory 320 for further processing.

The I/O subsystem 380 is configured to control an external input/outputdevice. Optionally, the I/O subsystem 380 may include the another inputdevice controller 381, a sensor controller 382, a display controller383, and a fingerprint controller 384. Optionally, one or more anotherinput device controllers 381 receive a signal from the another inputdevice 330 and/or send a signal to the another input device 330. Theanother input device 330 may include a physical button (such as apressing button), a camera, and the like. It should be noted that theanother input device controller 381 may be connected to any one or moreof the foregoing devices. The display controller 383 in the I/Osubsystem 380 receives a signal from the touch display screen 340 and/orsends a signal to the touch display screen 340. After the touch displayscreen 340 detects a user input, the display controller 383 converts thedetected user input into interaction with a user interface objectdisplayed on the touch display screen 340, to implement human-computerinteraction. The sensor controller 382 may receive a signal from one ormore sensors 360, and/or send a signal to one or more sensors 360. Thefingerprint controller 384 may receive a signal from the fingerprintdetector 350 and/or send a signal to the fingerprint detector 350.

As a control center of the mobile phone 300, the processor 390 connectsvarious parts of the entire mobile phone through various interfaces andlines, and performs various functions of the mobile phone 300 and dataprocessing by running or executing the software program and/or themodule that are stored in the memory 320 and by invoking data stored inthe memory 320, to perform overall monitoring on the mobile phone.Optionally, the processor 390 may include one or more processing units.Optionally, an application processor and a modem processor may beintegrated in the processor 390. The application processor mainlyprocesses an operating system, a user interface, an application program,and the like. The modem processor mainly processes wirelesscommunication. It should be understood that the modem processor may notbe integrated into the processor 390.

The mobile phone 300 further includes the power supply 3100 (forexample, a battery) that supplies power to each component. Optionally,the power supply may be logically connected to the processor 390 byusing a power management system, to implement functions such as chargingmanagement, discharging management, and power consumption management byusing the power management system.

Although not shown, the mobile phone 300 may further include anothermodule such as a Bluetooth module. Details are not described herein.

The following uses the mobile phone 300 as an example to describe indetail the fingerprint unlocking method provided in the embodiments ofthe present invention.

FIG. 4 is a schematic flowchart of a fingerprint unlocking methodaccording to an embodiment of this application. As shown in the figure,the method may include the following steps.

Step 401: When the mobile phone 300 is in a screen-locked state, theprocessor 390 determines whether an operation of a user meets a presetcondition.

Step 402: If it is determined that the preset condition is met, theprocessor 390 controls the touch display screen 340 to display afingerprint recognition identifier, where a display area of thefingerprint recognition identifier is an area in which fingerprintrecognition can be performed, namely, an area in which a fingerprintdetector is located.

In the foregoing method, when detecting that the operation of the usermay be an operation intended for fingerprint unlocking, the mobile phone300 displays the fingerprint recognition identifier in the area in whichfingerprint recognition can be performed, as shown in FIG. 5 , so thatthe user performs fingerprint recognition in the display area. Thisresolves a problem that the user cannot perform fingerprint recognitionbecause the user cannot see a position of the fingerprint detector.

Specifically, the screen-locked state may be a screen-off andscreen-locked state, or may be a screen-on and screen-locked state. Thescreen-on and screen-locked state indicates that a touch display screenis turned on, and information such as a date and time may be displayed,but a display screen does not display a home application screen oranother application screen. For example, a touch display screen of amobile phone is usually turned on after an on/off key of the mobilephone is pressed. However, if the user wants to use the mobile phone,the user further needs to perform an unlocking operation to enter thehome application screen or the another application screen of the mobilephone.

Optionally, when determining whether the operation of the user meets thepreset condition, the mobile phone 300 may determine a non-contactoperation of the user, or may determine a contact operation.

The non-contact operation may include a floating operation of a fingerof the user within a specific distance above the touch display screen,and may also include an operation such as sound control of the user.

In a possible implementation, the processor 390 in the mobile phone 300may determine, based on a capacitance signal of the touch display screen340, whether a floating operation of the finger of the user on the touchdisplay screen 340 meets the preset condition.

As described above, when a conventional terminal is in a screen-lockedstate, an integrated circuit of a touch display screen is usually in apower-off state, that is, the touch display screen is in a non-workingstate, and an operation of the user cannot be recognized. However, inthe foregoing manner, when the mobile phone 300 is in the screen-lockedstate, the processor 390 still needs to detect the capacitance signal ofthe touch display screen 340, to determine the operation of the user.

Specifically, a capacitive touch display screen may be classified into aself capacitive touch display screen and a mutual capacitive touchdisplay screen. A horizontal electrode array and a vertical electrodearray are disposed on the self capacitive screen, and these horizontaland vertical electrodes separately form a capacitor with the ground.When the finger touches the screen, or the finger does not touch thescreen but a distance between the finger and the screen is within aspecific range, a capacitance of the finger is superimposed on acapacitance of the screen, so that a capacitance value of the screen isincreased. When detecting an operation of the user, the self capacitivescreen separately detects capacitance values of the horizontal electrodearray and the vertical electrode array, and separately determines, basedon a change in capacitance before and after the user performs theoperation on the self capacitive screen, a horizontal coordinate and avertical coordinate of a position of the operation of the user. Ashorter distance between the finger of the user and the touch displayscreen indicates a higher capacitance value, and a longer distanceindicates a lower capacitance value. Therefore, the position of thefinger of the user and the floating operation may be analyzed based onthe capacitance signal.

For example, when the finger of the user is relatively far away from thetouch display screen, a detected capacitance signal may be shown in FIG.6(a). When the finger of the user is relatively close to the touchdisplay screen, a detected capacitance signal may be shown in FIG. 6(b).Compared with a capacitance value at a position marked by a block inFIG. 6(a), a capacitance value at a position marked by a block in FIG.6(b) is significantly increased. In addition, if a maximum capacitancevalue is located in the block area, it indicates that the user isrelatively close to the touch display screen at the position. It may beconsidered that the finger of the user is located above this area of thescreen, and the user may perform an operation on the mobile phone.

The processor 390 in the mobile phone 300 may determine, based on acapacitance signal generated by the floating operation of the user,whether the distance between the finger of the user and the touchdisplay screen 340 is less than or equal to a threshold. Generally, whenthe finger of the user is very close to the touch display screen 340 ofthe mobile phone 300, the user is more likely to use the mobile phone300. Therefore, when determining that the distance between the finger ofthe user and the touch display screen 340 is less than or equal to thethreshold, the processor 390 may control the touch display screen 340 todisplay the fingerprint recognition identifier, so that the user canperform fingerprint recognition in the area to unlock the screen.

For example, when it may be predetermined that the distance between thefinger of the user and the touch display screen 340 is a preset distancethreshold, the touch display screen 340 generates a value of acapacitance signal at the position of the finger of the user, and usesthe capacitance value as a preset threshold. When determining that thereis a capacitance value greater than or equal to the preset threshold inthe capacitance signal of the touch display screen 340, the processor390 determines that the distance between the finger of the user and thetouch display screen 340 is less than or equal to the threshold, anddisplays the fingerprint recognition identifier in the area in whichfingerprint recognition can be performed.

In addition, the processor 390 in the mobile phone 300 may determine,based on the capacitance signal generated by the floating operation ofthe user, whether a movement direction, of the finger of the user, thatis relative to the touch display screen 340 meets the preset condition.For example, if the finger of the user slides from an area far away fromthe area in which fingerprint recognition can be performed toward thearea in which fingerprint recognition can be performed, it is determinedthat the operation of the user meets the preset condition. In otherwords, it is considered that the user intends to unlock the screenthrough fingerprint recognition. In this case, the processor 390 maycontrol the touch display screen 340 to display the fingerprintrecognition identifier in the area in which fingerprint recognition canbe performed, so that the user can perform fingerprint recognition inthe area to unlock the screen.

Specifically, when determining a movement direction that is of the userand that is relative to the touch display screen 340, the processor 390in the mobile phone 300 may determine the movement direction of thefinger of the user based on a change in the capacitance signal detectedby the touch display screen 340 within a specific time period. Forexample, if a capacitance signal shown in FIG. 7 is detected at a momentt1, and a capacitance signal detected 0.5 seconds later is shown in FIG.6(b), it may be considered that the movement direction, of the finger ofthe user, that is above the screen is shown in FIG. 8 , and the fingerslides from a point A to a point B. Because a distance from the point Ato the fingerprint recognition area is greater than a distance from thepoint B to the fingerprint recognition area, it is determined that thefinger of the user slides from an area far away from the fingerprintdetector to an area close to the fingerprint detector. In this case, itmay be considered that the user intends to unlock the screen throughfingerprint recognition. Therefore, the processor 390 in the mobilephone 300 controls the touch display screen 340 to display thefingerprint recognition identifier, to prompt the user of the area inwhich fingerprint recognition can be performed, so that the user canperform fingerprint recognition in the area to unlock the screen.

It should be understood that the movement direction is merely an examplein this embodiment of this application, and the preset condition mayfurther include another preset movement direction. This is not limitedin this embodiment of this application.

Optionally, the preset condition may include that a distance between theuser and the touch display screen 340 is less than or equal to a presetthreshold, and further include that the movement direction that is ofthe user and that is relative to the touch display screen 340 meets thepreset condition. In other words, the user needs to meet that thedistance between the finger and the touch display screen 340 within apreset range, and makes a gesture that meets the preset condition.

In addition, the non-contact operation further includes sound controland the like. In a possible implementation, the processor 390 in themobile phone 300 may further receive an audio signal of the user throughan audio circuit, and display the fingerprint recognition area for theuser when the audio signal meets the preset condition. Optionally, whena voice activation manner is used, the integrated circuit of the touchdisplay screen may be in the power-off state. Certainly, the integratedcircuit of the touch display screen may not be powered off. To bespecific, when the mobile phone 300 is screen-locked, the mobile phone300 may control, based on a voice of the user, displaying thefingerprint recognition area, or may display the fingerprint recognitionarea based on an operation of the user on the touch display screen.

In a possible implementation, the processor 390 in the mobile phone 300may further perform the step 402 when determining that a contactoperation of the user on the touch display screen 340 meets the presetcondition. To be specific, the touch display screen 340 is controlled todisplay the fingerprint recognition identifier in the area in whichfingerprint recognition can be performed, so that the user can performfingerprint recognition.

Specifically, in this manner, the touch display screen still needs todetect the operation of the user when the screen is locked. Therefore,the integrated circuit of the touch display screen is not powered off.

Optionally, the processor 390 in the mobile phone 300 may determine,based on a signal generated by the operation of the user on the touchdisplay screen 340, whether the touch operation of the user meets thepreset condition. Currently, the capacitive touch display screen hasbecome a mainstream mobile phone screen. Therefore, for a mobile phoneprovided with a capacitive touch display screen, a processor maydetermine, based on a capacitance signal of the touch display screen,whether a touch operation of the user meets a preset condition.

In some embodiments, the user is in contact with the touch displayscreen 340. In other words, the preset condition is met. Specifically,if the touch display screen 340 is a capacitive screen, the processor390 may determine, based on the capacitance signal of the touch displayscreen 340, whether the user has performed the touch operation on thetouch display screen 340. For example, for the self capacitive touchdisplay screen, after the user touches the screen, a capacitance valueof a touch area increases. For the mutual capacitive touch displayscreen, after the user touches the screen, a capacitance value of atouch area decreases. The processor 390 may determine, based on a changein the capacitance value, whether the user is in contact with the touchdisplay screen 340.

In some other embodiments, the preset condition may include that an areain which the finger of the user is in contact with the touch displayscreen 340 is within the preset area. For example, to save power, whenthe screen is locked, the mobile phone 300 may perform scanningdetection on only a part of the touch display screen. In other words,the operation of the user can be recognized in an area in which scanningdetection is performed, and the operation of the user cannot be detectedin another area that is in a non-working state. The scanning detectionarea may include the area in which fingerprint recognition can beperformed. For example, if the fingerprint detector is disposed in alower half area of the touch display screen, only the lower half area ofthe touch display screen may be scanned and detected when the screen islocked. If the user touches the lower half area of the screen, it may beconsidered that the user intends to unlock the screen, and thefingerprint recognition identifier is displayed in the area in whichfingerprint recognition can be performed. If the user touches an upperhalf area of the screen, because the upper half area is in a non-workingstate and the operation of the user cannot be detected, the fingerprintrecognition area is not displayed.

It should be understood that the division of the area is merely aspecific embodiment. In actual application, the preset area may be setbased on different scenarios and different user requirements.

In some other embodiments, the preset condition may also include aquantity of times that the user taps the touch display screen, a slidinggesture of the user on the touch display screen, or the like. Forexample, if the user taps the touch display screen twice, thefingerprint recognition identifier is displayed for the user. Foranother example, if the finger of the user slides from an area far awayfrom the fingerprint recognition area to the fingerprint recognitionarea on the touch display screen, the fingerprint recognition area isdisplayed for the user. Specifically, the processor may determine thesliding operation of the user on the touch display screen 340 based onthe capacitance signal of the touch display screen 340. A determiningmethod is similar to the foregoing determining of the floatingoperation, but a change in a capacitance value generated by the floatingoperation may be different from a change in a capacitance valuegenerated by the contact operation.

Further, the preset condition may include a plurality of presetconditions. When the operation of the user meets the plurality of presetconditions, it is considered that the user intends to unlock the screen,and the fingerprint recognition area is displayed for the user. Forexample, if the user double-taps the screen, and a double-tap area islocated in the lower half area of the touch display screen, theprocessor 390 in the mobile phone 300 controls the touch display screento display the fingerprint recognition area.

As described above, the capacitive touch display screen may include theself capacitive touch display screen and the mutual capacitive touchdisplay screen. A horizontal electrode array and a vertical electrodearray are also disposed on the mutual capacitive touch display screen.When the finger touches the capacitive screen, coupling between twoelectrodes near a touch point is affected, thereby changing acapacitance between the two electrodes. Because the mutual capacitivetouch display screen can implement multi-point detection, the mutualcapacitive touch display screen is more widely applied. The foregoingdetecting, based on the capacitance signal, whether the contactoperation of the user meets the preset condition can be implemented byboth the self capacitive touch display screen and the mutual capacitivetouch display screen, but a change in a capacitance value before andafter a touch on each screen is different.

In addition, the touch display screen not only includes the capacitivetouch display screen, but also includes a resistive touch displayscreen, a touch display screen using a vector pressure sensingtechnology, a touch display screen using an infrared technology, a touchdisplay screen using a surface acoustic wave technology, and the like.In different types of touch display screens, it may also be determined,according to a working principle of each touch display screen, whether acontact area between the user and the touch display screen is within apreset range, and further, whether the fingerprint recognition area isdisplayed for the user.

Further, for a mobile phone that can detect both a contact operation anda non-contact operation on a touch display screen, a manner of detectingthe non-contact operation and the contact operation may also be used onthe mobile phone, to display a fingerprint recognition distinguishingarea to the user.

Optionally, the contact operation of the user on the mobile phone 300may further include a key operation. For example, an on/off key and/or avolume key are on a side of the mobile phone 300. The processor 390 inthe mobile phone 300 may alternatively display the fingerprintrecognition area to the user when determining that the key operation ofthe user meets the preset condition. The preset condition may be thatthe user presses the on/off key, the user presses the volume key, or theuser simultaneously presses a volume-up key and a volume-down key. In aspecific embodiment, when the mobile phone 300 is in the screen-lockedstate, if the processor 390 in the mobile phone 300 detects that theuser presses the on/off key, the processor 390 controls the touchdisplay screen 340 to display the fingerprint recognition identifier inthe area in which fingerprint recognition can be performed. As describedabove, when a conventional mobile phone is in a screen-locked state, afingerprint detector is in a working state.

In the embodiments provided in this application, the fingerprintdetector in the mobile phone may also be continuously in the workingstate when the mobile phone is in the screen-locked state, so that whenthe user is familiar with the fingerprint recognition area of theterminal, even if the mobile phone does not display the fingerprintrecognition area, the user may directly place the finger in thefingerprint recognition area to perform fingerprint recognition, tosimplify the operation of the user. In some other embodiments, when themobile phone 300 is in the screen-locked state, the fingerprint detectorin the mobile phone 300 may also be in a power-off state, namely, anon-working state. Therefore, an unlocking misoperation of the user whenthe user holds the mobile phone but does not use the mobile phone can beavoided. If the mobile phone unlocks the screen without the user'sknowledge, more misoperations may occur. For example, a call is made bymistake. In addition, unlocking the screen by mistake consumesrelatively more power.

To clearly understand the foregoing embodiments of this application, thefollowing provides detailed descriptions with reference to FIG. 9 andFIG. 10 .

FIG. 9 shows an example of a process in which a mobile phone unlocks ascreen based on a gesture of a user.

Step 901: The mobile phone is in a screen-locked state.

Step 902: A processor determines, based on a capacitance signal of atouch display screen, whether the user performs an operation. If anoperation of the user is detected, step 903 is performed.

Step 903: The processor determines whether a finger of the user slidesfrom an area far away from a fingerprint recognition area toward thefingerprint recognition area, and if yes, step 904 is performed.

Step 904: The processor controls the touch display screen to display thefingerprint recognition area, and enables a fingerprint detector.

Optionally, if the fingerprint detector is always in a working state, astep of enabling the fingerprint detector is not required herein.

Step 905: The processor determines, through the fingerprint detector,whether there is a valid fingerprint input, and if yes, step 806 isperformed.

Step 906: The processor unlocks the touch display screen.

FIG. 10 shows an example of a process in which a mobile phone unlocks ascreen based on a contact operation of a user on a touch display screen.

Step 1001: The mobile phone is in a screen-locked state.

Step 1002: The processor determines, based on a capacitance signal ofthe touch display screen, whether the user double-taps the touch displayscreen in a preset area, and if yes, step 1003 is performed.

Step 1003: The processor controls the touch display screen to display afingerprint recognition area, and enables a fingerprint detector.

Optionally, if the fingerprint detector is always in a working state, astep of enabling the fingerprint detector is not required herein.

Step 1004: The processor determines, through the fingerprint detector,whether there is a valid fingerprint input, and if yes, step 905 isperformed.

Step 1005: The processor unlocks the touch display screen.

Based on a same technical concept, an embodiment of this applicationfurther provides a terminal, to implement the foregoing methodembodiments. A structure of the terminal may be shown in FIG. 3 , but isnot limited to the terminal shown in FIG. 3 . The terminal may include aprocessor, a touch display screen, and a fingerprint detector. Thefingerprint detector is built in the terminal.

The processor is configured to:

when the terminal is in a screen-locked state, determine whether anoperation of a user meets a preset condition; and

if the operation of the user meets the preset condition, control thetouch display screen to display a fingerprint recognition identifier,where a display area of the fingerprint recognition identifier is anarea in which fingerprint recognition can be performed.

In a possible implementation, the operation of the user is that the usertouches the touch display screen or performs a floating operation on thetouch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether the capacitance signal isgreater than or equal to a capacitance value of a preset threshold, oris less than or equal to the capacitance value of the preset threshold.

In a possible implementation, the operation of the user is that the userperforms a floating operation on the touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether a distance between afinger of the user and the touch display screen is less than or equal toa preset threshold.

In a possible implementation, the operation of the user is that the usertouches the touch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether an area in which a fingerof the user touches the touch display screen is in a preset area, wherethe preset area is the area in which fingerprint recognition can beperformed.

In a possible implementation, the operation of the user is that the usertouches the touch display screen or performs a floating operation on thetouch display screen.

The processor is specifically configured to:

determine, based on a capacitance signal generated by the operation ofthe user on the touch display screen, whether a finger of the userslides from an area far away from the area in which fingerprintrecognition can be performed toward the area in which fingerprintrecognition can be performed.

In a possible implementation, the operation of the user is that anoperation of the user on a phone key.

The processor is specifically configured to:

determine, by the terminal based on a signal generated by the operationof the user on the phone key, whether the user presses an on/off key ora volume key, or whether the user simultaneously presses a volume-up keyand a volume-down key.

In a possible implementation, after determining that the operation ofthe user meets the preset condition, the processor is further configuredto enable or disable a fingerprint detector.

It may be understood that, for the terminal embodiment, reference may bemade to the detailed descriptions of the method embodiments, and detailsare not described herein again.

A person skilled in the art should understand that the embodiments ofthis application may be provided as a method, an apparatus, or acomputer program product. Therefore, this application may use a form ofa hardware embodiment or a software embodiment. In this embodiment ofthis application, one or more computer-usable storage media includingcomputer-usable program code may be used. For example, a memory, a flashmemory, a read-only memory (Read Only Memory, ROM), an erasableprogrammable read-only memory (Erasable Programmable ROM, EPROM), anelectrically erasable programmable read-only memory (Electrically EPROM,EEPROM), a register, a hard disk, a removable hard disk, a compact discread-only memory (Compact Disc Read-Only Memory, CD-ROM), or a form of acomputer program product implemented in any other form of storage mediumwell known in the art may be used.

Apparently, equivalent replacements, improvements, and the like made bya person skilled in the art based on the technical solutions of thisapplication should all fall within the protection scope of thisapplication.

What is claimed is:
 1. An electronic device, comprising: a screen; oneor more processors; and a memory coupled to the processor and forstoring instructions which, when executed by the one or more processors,cause the electronic device to: lock the screen of the electronicdevice; detect a floating gesture of a user when the screen is lockedand in response to detecting the floating gesture display a fingerprintrecognition identifier in a fingerprint recognition area of the screen;detect a first touch gesture of the user on the fingerprint recognitionidentifier thereby to obtain a first fingerprint of the user, andprocess the first fingerprint to identify whether the first fingerprintis valid; unlock the screen when the first fingerprint is valid; detecta non-contact operation of the user; lock the screen of the electronicdevice in response to detecting the non-contact operation; while thescreen is locked and not displaying the fingerprint recognitionidentifier, detect a second touch gesture of the user in the fingerprintrecognition area, and process the second touch gesture to obtain asecond fingerprint of the user; and unlocking the screen when the secondfingerprint is valid.
 2. An electronic device, comprising: a screen; oneor more processors; and a memory coupled to the one or more processorsand for storing instructions which, when executed by the one or moreprocessors, cause the electronic device to: lock the screen of theelectronic device; detect a first operation of a user while the screenis locked and in response to detecting the first user operation displaya fingerprint recognition identifier in a fingerprint recognition areaof the screen; detect a second operation of the user on the fingerprintrecognition identifier and process to obtain a first fingerprint of theuser; unlock the screen when the first fingerprint is valid in responseto detecting the second operation; detect a third operation of the user;lock the screen of the electronic device in response to detecting thethird operation; while the screen is locked and not displaying thefingerprint recognition identifier, detect a fourth operation of theuser in the fingerprint recognition area, and process to obtain a secondfingerprint of the user; and unlock the screen when the secondfingerprint is valid.
 3. The electronic device according claim 2,wherein the instructions executed by the one or more processors furthercause the electronic device to: detect the fourth operation of the userwhen nothing is displayed on the screen, wherein the fourth operation isin a first area of the screen other than the fingerprint recognitionarea; and maintain the screen displaying nothing.
 4. The electronicdevice according to claim 2, wherein the first operation is anon-contact operation.
 5. The electronic device according to claim 4,wherein the non-contact operation comprises a motion sensing operation,or a floating operation.
 6. The electronic device according to claim 2,wherein the second operation is a touch gesture.
 7. The electronicdevice, according to claim 2, wherein the third operation is anon-contact operation.
 8. The electronic device according to claim 2,wherein the fourth operation is a touch gesture.
 9. The electronicdevice according to claim 2, wherein the fingerprint recognitionidentifier is an icon for prompting the user to perform fingerprintrecognition.
 10. The electronic device according to claim 2, furthercomprising: a fingerprint detector; and wherein the instructions which,when executed by the one or more processors, further cause theelectronic device to, after detecting the third operation and lockingthe screen in response thereto, place the fingerprint detector in aworking state.
 11. The electronic device according to claim 2, whereinthe first operation comprises pressing an on/off key or a volume key onthe electronic device.
 12. A non-transitory computer-readable mediumincluding computer-executable instructions, which, when executed by aprocessor, cause the processor to perform a method comprising: lockingthe screen of the electronic device; detecting a first operation of auser when the screen is locked and in response to detecting the firstuser operation displaying a fingerprint recognition identifier in afingerprint recognition area of the screen; detecting a second operationof the user on the fingerprint recognition identifier and processing toobtain a first fingerprint of the user; unlocking the screen when thefirst fingerprint is valid in response to detecting the secondoperation; detecting a third operation of the user; locking the screenof the electronic device in response to detecting the third operation;while the screen is locked and not displaying the fingerprintrecognition identifier, detecting a fourth operation of the user in thefingerprint recognition area, and processing to obtain a secondfingerprint of the user; and unlocking the screen when the secondfingerprint is valid.
 13. The computer-readable medium according toclaim 12, wherein the method performed by the processor furthercomprises: detecting the fourth operation of the user on a first areawhen nothing is displayed on the screen, wherein the fourth operation isin a first area of the screen other than the fingerprint recognitionarea; and maintaining the screen to display nothing.
 14. Thecomputer-readable medium according claim 13, wherein the non-contactoperation comprises a motion sensing operation or a floating operation.15. The computer-readable medium according to claim 12, wherein thefirst operation is a non-contact operation.
 16. The computer-readablemedium according to claim 12, wherein the second operation is a touchgesture.
 17. The computer-readable medium according to claim 12, whereinthe third operation is a non-contact operation.
 18. Thecomputer-readable medium according to claim 12, wherein the fourthoperation is a touch gesture.
 19. The computer-readable medium accordingto claim 12, wherein the fingerprint recognition identifier comprises anicon for prompting the user to perform fingerprint recognition.
 20. Thecomputer-readable medium according claim 12, wherein the methodperformed by the processor further comprises: after detecting the thirdoperation of the user and locking the screen of the electronic device inresponse thereto, placing a fingerprint detector in a working state,wherein the fingerprint detector is built into the electronic device.